package com.example.myfirstapp;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.widget.TextView;

/**
 * 入口主界面
 * @author lijiguo
 */
public class MainActivity extends AppCompatActivity {

    // 定义TextView类型的变量
    private TextView tvHello;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // 获取tvHello对象
        tvHello = findViewById(R.id.tv_hello);

    }
}